The present invention relates to an automatic control system for an engine of vehicles, and more particularly to an improvement of the engine control system such as disclosed in U.S. Pat. No. 3,731,108 dated May 1, 1973, German Pat. No. 2,158,095 dated Sept. 6, 1973 and French Pat. No. 7,139,281 dated July 10, 1972.
In the engine control system disclosed in the mentioned Letters Patents, an engine is automatically stopped when the vehicle is arrested and the engine is automatically driven in response to the depression of the clutch pedal for starting the vehicle, both operations being carried out without operating the ignition switch. Repeated engine starting consumes electric energy out of a battery of the vehicle in a short period of time. Besides, as a modern fashion there is a tendency that a vehicle is installed with more numbers of electrically operated accessory devices. On the other hand, the stored capacity of a vehicle battery becomes rather smaller due to the improved high generating efficiency of an alternator.
It is very dangerous if the engine cannot be restarted after it is automatically arrested at a crossing or the like because of shortage of the electric energy out of the vehicle battery. It should be, therefore, very important in installation of an engine automatic control system of this kind to avoid any possible inconvenience and dangers caused by the shortage of the electric energy.